1 / 30

Exploring Interference Effects in D Meson Decays

This paper discusses the significance of interference effects in D meson decays, outlining new results from CLEO experiments since 2005. The research covers topics such as quantum correlations, Dalitz analyses, and quantum correlation analysis (TQCA). Preliminary data on D▶KKπ and D▶3π decays are highlighted, along with insights into strong phase differences and mixing parameters. The study underscores the importance of interference effects in extracting fundamental parameters. Experimental setups, data sets, and methods used by CLEO are detailed to shed light on the complexities of D meson decay processes.

berube
Download Presentation

Exploring Interference Effects in D Meson Decays

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Interference Effects in D Meson Decays D. Cinabro Wayne State University FPCP 2006, 12 April

  2. Why Interference Effects? • Provide unique information • Phases and amplitudes are otherwise inaccessible • Need these to extract fundamental parameters (CKM elements for example) from other measurements • Challenge and input for QCD

  3. Outline New results (since summer 2005) are thin • DKK0 Dalitz analysis for DKK* strong phase from CLEO-III • D3 Dalitz analysis from CLEO-c • Quantum Correlations in D0D0 decays from the ’’ for phases and mixing parameters from CLEO-c _

  4. CLEO Data Sets • CLEO-III data on (4S), 9/fb with charm produced in continuum or from B decay • CLEO-c data on the ’’, 281/pb, which corresponds to 1.4M D pairs.

  5. CLEOc Detector Venerable CsI Calorimeter 2.2% resolution on 1 GeV photon, 5% on 100 MeV, p/p = 0.6% at 1 GeV, RICH particle ID

  6. CLEO-III: DKK0 • Motivation is to extract strong phase difference in DK*K • See Grossman, Ligeti, and Soffer (PRD 67(2003)07130) and Rosner and Suprun (PRD68(2003)054010) for how this helps measure CKM  (3) in charged B decay

  7. DKK0: Charged D* Tag • 600 Signal S:B=4:1, Soft  tag gives D0 flavor

  8. DKK0 • Both charges of K* and  contributions clearly visible • Interference between K*’s is also clear

  9. DKK0

  10. CLEO-III: DKK0 • Preliminary • DK*K = 332o±8o±11o, large interference • |A(DK*-K+)|/ |A(DK*+K-)|= 0.52±0.05±0.04 • Precision limited by non-K* contributions to the decays • Observed branching fractions consistent with previous measurements

  11. CLEO-c: D3 Dalitz First time doing a Dalitz analysis that has been done by E791 and FOCUS (previously concentrated on modes with 0) 2600 signal on S:B of 2:1 (E791 1200, FOCUS 1500) Mbc = Ebeam2 + p32, E = Ebeam - E3 __________

  12. D3 Dalitz • Symmetry under interchange of like-sign pions • Dalitz analysis on high mass versus low mass unlike-sign pion combinations • Big vertical stripe is Ks

  13. D3 Dalitz • Worry that efficiency will be difficult in corners of the Dalitz plot since D+ starts nearly at rest. • Looks good, changes are smooth. • Model with both MC bin-by-bin and polynomial fit.

  14. D3 Dalitz • Backgrounds from sidebands (offset in E to insure that it remains on the Dalitz plot) • Add in Ks, , f0(1370) to represent possible resonance contributions

  15. D3 Dalitz: Many potential contributions

  16. f2  D3 Dalitz  f0

  17. D3 Dalitz

  18. CLEO-c: D3 Dalitz • Still preliminary • Need to consider other models of  S-wave (for example replace  and f0 contributions by generalized  interaction) to compare with FOCUS which used the K-matrix • Broad agreement with E791 ( contribution, first observation for CLEO)

  19. The Quantum Correlation Analysis ee*D0D0 is C -1 K-+ vs K+- interfere and thus sensitive to DCSD and strong phase Time integrated rate depends on both cosDK and mixing parameter y = /2 K-+ vs K-+ forbidden unless there is mixing. K-+ vs semileptonic measures isolated decay rate and tags flavor of decaying D Different sensitivity to mixing vs DCSD D decays to CP eigenstates also interfere and opposite semileptonics to get isolated rate, flavor tags for yet another dependence on y and strong phase CP eigenstate vs CP eigenstate shows maximal correlations CLEO-c: TQCA -

  20. See PRD 73 034024 (2006) [hep-ph/0507238] by Asner and Sun TQCA RM= (x2+y2)/2 r = Amp DCS/Amp CF - And measure branching fractions simultaneously

  21. TQCA: Single Tags in Data K-+ K+- KK Ks0 Ks00 

  22. TQCA: Double Tags in Simulation M(K-+) M(K-+) M(K+-) M(K-+) M(KK) M(KK) M(K-+) M(KK)

  23. TQCA:Semileptonics Opposite K Flavor Tag Opposite CP- Tag Signal Backgrounds Electron Momentum (GeV) Electron Momentum (GeV)

  24. CP tags vs CP tags clearly shows Quantum Correlation TQCA CP+ CP- C P + CP-

  25. TQCA K-+ vs K-+ K-+ vs K+- Data clearly favors QC interpretation showing constructive and destructive interference and no effect as predicted CP+ vs CP+ CP- vs CP- CP+ vs CP- K vs CP+ K vs CP-

  26. CLEO-c: TQCA • Obviously still preliminary, but very promising • Systematics look tractable (< stats) • Number of CP tags is limit so working on adding more • C+ fraction < 0.06±0.05±? on ’’ • Ultimate sensitivity with projected CLEO-c data set y ±0.012, x2 ±0.0006, cosDK ±0.13, x(sinDK) ±0.024 (needs C+1 initial state from running above the ’’)

  27. Conclusions • Unique information from interference effects in D decays • All since summer 2005 from CLEO • DK*K = 332o±8o±11o and |A(DK*-K+)|/ |A(DK*+K-)|= 0.52±0.05±0.04 in DKK0 Dalitz • D3 Dalitz agrees with E791 on need for low mass  S-Wave contribution • CLEO TQCA sensitive to D mixing parameters and DK

More Related